Catheters may be located in various venous locations and cavities throughout the body of a patient for introduction of fluids to a body or removal of fluids from the body. Such catheterization may be performed by using a single catheter having multiple lumens. A typical example of a multiple lumen catheter is a dual lumen catheter assembly in which one lumen introduces fluid and the other lumen removes fluid. An example of such a dual lumen catheter assembly is the SPLIT-CATH® catheter. Alternatively, catheterization may be performed by using multiple single-lumen catheters, such as TESIO® catheters.
Generally, to insert any catheter into a blood vessel, the vessel is identified by aspiration with a long hollow needle in accordance with the well known Seldinger technique. When blood enters a syringe attached to the needle, indicating that the vessel has been found, a thin guidewire is then introduced, typically through a syringe needle or other introducer device into the interior of the vessel. The introducer device is then removed, leaving the guidewire within the vessel. The guidewire projects beyond the surface of the skin. At this point, several options are available to a physician for catheter placement. The simplest is to pass a catheter into the vessel directly over the guidewire. The guidewire is then removed, leaving the catheter in position within the vessel. However, this technique is only possible in cases where the catheter (for example, a small diameter dual lumen catheter) is of a relatively small diameter, made of a stiff material, and not significantly larger than the guidewire. If the catheter to be inserted is significantly larger than the guidewire, a dilator device containing a sheath is passed over the guidewire to enlarge the opening in the vessel. The dilator is then removed along with the guidewire, leaving the sheath in place, and the catheter is then passed through the sheath into the vessel. The guidewire is then removed, leaving the catheter in position within the vessel.
Each catheter lumen is typically connected to a distal end of an extension tube via a hub. The extension tube has a standard connector at its proximal end for connection to a medical device, such as a hemodialysis machine. Such connectors are commonly referred to as “luers”. A luer includes standard male threads for connection of a cap to the luer when the luer is disengaged from the hemodialysis machine to prevent blood from flowing out of the catheter. As a backup to the cap, a clamp, such as a Roberts clamp, is typically disposed over the extension tube. The clamp restricts fluid flow through the extension tube by compressing and closing the extension tube between a pair of clamp jaws. For long term catheterization, the clamp must be opened and closed numerous times, which may lead to a failure of the extension tube and blood loss from the catheter. It would be beneficial to provide an alternate method of providing a backup for the cap to secure the catheter between dialysis treatments.